1. Field of the Invention
The present invention relates to a ceramic multilayer substrate, and more specifically to a ceramic multilayer substrate including an end surface electrode in addition to an electrode disposed on a main surface thereof.
2. Description of the Related Art
Some of the proposed ceramic multilayer substrates including a plurality of ceramic layers have an end surface electrode disposed at an end surface other than the main surfaces of the main body of the substrate.
For example, Japanese Unexamined Patent Application Publication No. 2000-277916 proposes that an end surface electrode 2 be formed, as shown in the sectional views of FIGS. 11 and 12 and the perspective view of FIG. 13. In this instance, a cross through-groove is formed in the thickness direction in a substrate main body 10 including ceramic layers 10a to 10h. An electroconductive member 13 is formed by filling the cross through-groove with an electroconductive paste. The electroconductive member 13 is divided into end surface electrodes 2 by a dividing groove 15. Then, an anchor electroconductive member 7 is connected to the end surface electrode 2 to prevent the end surface electrode 2 from separating from the substrate main body 10.
However, the anchor electroconductive member is formed to a depth equal to the thickness of the end surface electrode in the thickness direction of the substrate main body, and the ceramic of the substrate main body and the metal of the anchor electroconductive member have a difference in thermal shrinkage. This difference makes it difficult to completely prevent the metal end surface electrode from separating or falling.
When the substrate main body is sintered, the ceramic layers shrink in the main surface direction of the substrate main body. Accordingly, a crack occurs between the end surface electrode and the substrate main surface to reduce the strength of the substrate.